These days LED video walls are about as common at concerts as T-shirt vendors, so it’s difficult to imagine that these panels were all but unheard of just a few short years ago.
The technology behind video walls has drastically changed since their introduction and has become ubiquitous in retail stores, events and more.
But what exactly is a black body SMD and how do you determine the right pixel pitch for the specific installation?
As part of its ‘Lighting Insights’ blog, Chauvet Professional targeted all questions relating to the world of video walls towards the company’s senior product manager, Ford Sellers.
We see PVP and MVP in Chauvet Professional catalogs and on the website. What’s the difference? Why two names and not one?
Great question. Just as we have several different models of lighting fixtures, designed for different applications and to meet different customer demands, we also have different models of video walls to meet our customer’s needs and expectations.
The MVP was our touring ‘curtain style’ product, with wider pixel pitch, high brightness and high transparency.
As our customers demanded tighter pitch (for closer viewing distances), we developed the PVP S series.
The PVP S series of panels have pixel pitches down to 5mm and these are optimised for faster setup and have brightness that is appropriate for touring, as well as A/V rental and applications.
The CHAUVET Professional website and literature describes the C6 video panel as being for permanent applications. Can you explain what that means?
We developed the C6 to maximise value for permanent installations.
By removing some of the touring features and increasing the panel size, we were able to realise huge savings for our customers who do not need to set the wall up and tear it down every day.
Then, on the other side of the coin, we have launched our PVP X Series.
The panels in this series are specifically designed for touring.
There are currently two panels in the series: A P6 outdoor rated panel and a P3 indoor rated one.
We have taken all of the lessons learned on our previous panels and designed these panels with rugged die-cast frames.
Both panels are front serviceable utilising magnetic LED modules.
The PVP X6IP is designed for outdoor applications where high contrast and high resolution and high brightness (to compete with daylight) are required.
The PVP X3 is designed for closer viewing distances in indoor applications where high resolution is a must.
Backing up for a moment, am I giving up anything with the C6 panels?
Absolutely, because it’s not intended for touring.
I like to compare it to buying a Humvee to drive the corner grocery store.
Sure you can do it, but you can maximise your budget if you pick a more appropriate vehicle for the task.
The same logic applies to the C6 – it’s about getting the most appropriate product for your application.
Our C6 removes the options that are targeted to the touring industry.
An installation panel is intended to be installed one time usually in a fixed location, on a solid wall.
This means that it does not need to stand-up to the rigors of touring. It also does not need to come packaged in a road case.
Plus, each panel can be twice as large, so there are fewer components like power supplies, connectors, cables and receiver cards.
All of these small savings add up to a large difference in the price of a new video wall without compromising the quality, performance or longevity of that product in its intended application.
What is a ‘blackface SMD LED’ and why is it important?
This is a complex subject, so I will give you the short version.
SMD means ‘Surface Mounted Device.’
This simply means that these are LEDs mounted directly on a PCB. This allows them to appear very small and be mounted very closely together, which decreases the pixel pitch, for higher resolution.
The alternate (older) technology utilises the LEDs that have wires extending out of the back and are usually bubble encapsulated.
In video wall, the latter type of LED is referred to as DIP and is typically now only used for outdoor signage (video billboards), where viewing distances are very far, because their image quality can be a little lower.
The terms ‘blackface’ and ‘black body’ relate to how the SMD LEDs are mounted to the LED PCB.
Blackface LEDs have a black surface between the LEDs, but the material that the LED is mounted in and the area directly around the LED, are white to act as a reflector to increase brightness.
This also makes the apparent size of the LED source slightly larger, which reduces contrast.
You may see this technology used in applications where brightness is critical, like outdoor touring panels and in panels with pixel pitches of five or higher.
Black body LEDs are mounted in a black substrate. This means that there is no white area around the LEDs, so that you can attain the highest possible contrast.
This can aid in image clarity and crispness, but usually means that the overall brightness is less than a blackface LED of the same size and power.
We use blackbody LEDs in our PVP X3, as image quality is critical and these panels have a very tight pixel pitch.
Speaking of pixel pitch, can you explain how it differs among different video panels? How do I determine which pixel pitch is right for my project?
Pixel pitch is the centre-to-centre measurement between adjacent LEDs. This tells you the minimum ideal viewing distance.
The rule of thumb is that your minimum viewing distance (in meters) is equivalent to your pixel pitch in millimetres.
So for a display made with panels which have a pixel pitch of 3.9, you would want for the majority of your audience to be 12’ 8” or further from the display.”
What about refresh rate and NITS; what do they mean and why do they matter?
Refresh rate is measured in hertz and is how many times the LEDs refresh per second.
This may be an issue when you are filming your show.
Refresh rates below 600hz may appear to flicker on-camera.
You will likely want to have refresh rates of 1200hz or greater for higher resolution panels.
NITS is a measurement of brightness in video walls. It is the number of candela produced per square metre.
Typically indoor panels are rated between 1200 and 1500 NITS and outdoor panels need to be rated above 4000-4500 NITS to be able to compete with the ambient light during the day – the sun is really, really bright!
Another thing that we often get questions about is the IP 65 rating on panels like the PVP X6IP. What exactly does the IP 65 rating mean?
IP stands for ingress protection. For Chauvet, this relates to application.
It is important for a customer to know whether or not a product can be safely used outdoors, where it may be exposed to weather.
With IP ratings, the first and second digits refer to different types of protection.
The first digit is for solid particle protection. A 6 here means that no dust can get into the fixture.
The second digit refers to liquid ingress protection. A 5 here means that water projected by a nozzle against the fixture from any direction shall have no harmful effects.
So regardless of where the water comes from, it will not get into the video walls and cause damage.
You gave us a lot of good information about video panels. So now can you tell us a little about the VIP media server and VIP Signal Processor? What do they do?
The short and accurate answer is – content delivery!
Your video wall can only look as good as the images that you show on it.
When you invest in a video display, you want to be sure that it looks as good as it possibly can.
A media server is a specialised computer that houses all of your content and serves up a hot plate of video-goodness to your display!
It uses specialised video processors to make sure that your content can be delivered reliably and without jitter.
The VIP Media Server stores up to 500GB of content on a solid state hard drive (SSD) for extra reliability.
It houses all of the software for setting up and configuring your video system and even integrating it into your lighting system – triggering the software via DMX or ArtNet.
It has video inputs and outputs in all major video formats like HDMI, SDI, SVideo and Component.
This allows you to mix, manipulate and deliver content to your PVP Video walls, in addition to video projectors and other types of displays.”
What about the VIP Signal Processor?
The VIP Signal Processor is a rack mounted switcher/scaler that allows you to mix and transition between multiple video sources.
It can be controlled via its push-button face place, or by connecting it to a computer via USB.
The VIP 5162. Signal Processor lets you manipulate things like scaling, contrast, brightness, colour correction and enables you to do fades, wipes, an even manage picture-in-picture effects without using a media server.
This is especially useful when you are not generating your content locally and are simply switching between content source delivered via SDI, DVI, USB, VGA, CV or Display port.
Content is critical in video walls and I’m happy to report that Chauvet Professional has the tools that will help you deliver and display it in excellent fashion.